Method for making sheet metal v-pulleys



March 22, 1960 F. ZATYKO, SR

METHOD FOR MAKING SHEET METAL V-PULLEYS 6 Sheets-Sheet 1 Filed Jan. 3,1950 VIIIII'III I a 0 I 0 0 IIIII'IIIIIIIIIIIffllfillllllfl" mu u n I la I I I I I I 1m 'IIIIIIIIIIIIII Frank Zatyko March 22, 1960 F. ZATYKO,sR 2,929,345

METHOD FOR MAKING SHEET METAL V-PULLEYS Filed Jan. 3, 1950 6 SheetsSheet2 Frank Zatyko 6 Sheets-Sheet 3 Frank Zatyko 21 m m m m l aw \& NN 5.RNMSN .lk & N

March 22, 1960 F. ZATYKQ, SR

METHOD FOR MAKING SHEET METAL V-PULLEYS Filed Jan. 3, 1950 GNN METHOD FOR MAKING SHEET METAL V-PULLEYS This invention relates to V-pulleys ofone-piece, stamped sheet metal construction. This application is acontinuation-in-part of my copending application for Method of Making aPulley Serial No. 767,670, filed August 9, 1947, now US. Patent No.2,493,053.

This invention relates to stamped sheetmetal onepiece multiple-V as wellas to single V-pulleys. Not only does such stamped sheet metalconstruction reduce the ultimate cost of such pulleys, but pulleys madeaccording to this invention are stronger, more durable, and moreaccurately sized and balancedthan prior art sheet metal pulleys madefrom sheet metal of equal gauge. Single pulleys made according to thisinvention thus permit the use of metal which is several gauges lighterthan that heretofore specified for pulleys of equal strength.

As far as is known, the prior art never produced onepiece multiple-Vsheet metal pulleys. Either machined cast multiple V-pulleys wereemployed or two or more single-V sheet metal pulleys were joinedtogether. Neither prior art construction has proved to be bothsatisfactory and economical. The cast and machined pulatent leys havebeen expensive and the strength and concert- I tricity of the joinedsheet metal pulleys was poor.

1 The greater strength of sheet metal pulleys made according to myinvention results from the fact that uniform gauge is maintainedthroughout the folds of the metal pulley, whereas the prior art methods,principally spinning, caused a stretching and thinning of the metal ofthe pulley, particularly at the roots of the Vs in the pulleys. In fact,the stretching and drawing of the metal.

in prior art pulleys created such lines of weakness that minimumthicknesses were characteristically specified at these points and it wasimpractical to produce a pulley having a single sharp V-fold at the rootof the pulley grooves. Such sharp V-folds may be provided in pulleysmade according to my invention (see Figs. 10 to 18) without thinning.

Another factor contributing to the strength of my pulley is that themetal therein is not subject to over-working during the forming of thepulley. In my pulley, the sheet metal is worked only to. the extentnecessary to shape the cups from which the pulleys are formed and tofold the metal to form the V-grooves. In the prior art, similarappearing single-V pulleys could be formed by spinning, but in sospinning the pulleys, the metal was so drawn and stretched that it wassubject to cracks and fracture, particularly in the thinned areas.

Arcuate sizing, balance, and concentricity are obtained due to the factthat the grooves are substantially coined in the finishing operations.Due to the smoothness and concentricity obtainable, belt wear andpossible fatiguing of the metal in the pulley (due to shifting loadsresulting from eccentricity) is minimized. Y I

Other objects and advantages will be apparent from the followingdetailed description of the method in which particular reference will bemade to the accompanying drawingsand in which Figures 1 to 6, inclusive,show the successive stages I 2,929,345 Patented Mar. 22, 1960 ,2 in thisprocess of stamping a single-V pulley from a sheet metal blank, eachview being partially in elevation and partially in verticalcross-section,

Figure 7 is a vertical cross-section of the stamping dies just-beforethe stamping operation for forming the inner pulley flange as shown inFigure 5,

Figure 8 is a vertical cross-sectional view of the dies similar toFigure 7 but showing the dies immediately after the stamping operationhas been carried out,

Figure 9 is a vertical cross-section of the dies immediately aftercarrying out the final stamping operation for the single-V pulley,

Figures 10 to 15 are fragmentary cross-sections of the stamping dies orthe timing rolls showing successive steps in forming a double-V pulleyhaving an inner V-groove' 0t slightly lesser diameter than the outerV-gr'ooves,

Figure 16 is an elevation, partly broken away, showing the double-Vpulley formed by the steps of Figures 10 to 15, and

Figures 17 and 18 are enlarged fragmentary views showing the stepsemployed in forming a double-V.pulley having V-grooves of equaldiameter. I 7

With reference to Figures 1 to 6, inclusive,"a piece of sheet metalis'first stamped to form a cylindrical cupshaped blank 11, having a baseor web 12 as shown in Figure 1. The blank 11 is then 'stamped'and drawnto form the outwardly flared flange 13, asshown in Fig: ure 2. Thisoperation also reduces .the diameter of the blank and increases itslength or depth; .The depth of the blank at this stage, i.e. thedistance from the web 12 to the flange 13, determines to a large extent,though not exclusively, the final location of the ;web with respect tothe groove of the finished pulley. The next operation, as shown inFigure 3, consists in spreading the flange 13 to correspond withtheouter flange of the finished pulley. The blank 11 is then stamped asshown in Figure 4 to trim the edge of the flange 13 and to provide aflanged edge. This completes the stamping operation for forming theouter flange of the pulley and the blank 11, at this stage will betermed a preformed cylindrical cup-shaped blank.

Figure 5 showsan annular bulge 14 which is formed around the cylindricalwall of the blank 11 and which is ultimately formed into the innerflange 15 of the pulley, as shown in Figure 6. Y Y

The operation for forming the bulge 14is carried out by applyingpressure to the base 12 of the blank 11, and at the same timeby,applying outward radial pressure against the cylindrical wall of theblank 11 at the point where the bulge 14 is to be formed. The mannerxofcarrying out this operation will be more fully described hereinafter. I

Figure 6 shows the finished pulley in which the bulge 14 has beencrimped together to form the flange 15, the flanges 13 and 15 formingthe'pulley groove 16. To accomplish this, pressure is .applied onopposite sides of the crown of thebulge 14 to fold the metal flat uponitself in the manner shown.

As shown in Figure6, the ;web 12 of the finished pul-' ley is spacedfrom the plane of the peripheral groove 16; If desired the web 12 of thepulley may lie in the same plane as the groove 16 or within the generalplane of the inner flange 15m in any other desired plane depending uponthe use for which the pulley is designed. The pulley shown in Figure 6is especially designed for use as a fan-belt pulley in automobiles. I 1a 3 ,With reference to Figure 7a stampingpress is shown which includes,a die holder 20 and a form punch 21 removably secured thereto in anyconventional manner; The form punch 21 is shapedto receive the flange 13of the blank 11 after it has been preformed as seen in Figure.

4. A pair of semi-circular slide form blocks 22, which constitute asplit ring assembly, are slidably mounted on the holder 26. A portion ofthe blocks are'shaped to complement the form punch 21 so that the blank11 will be gripped around the flange 13 during the stamping operation, Avertically movable punch holder 23 is located above the die holder '20and its associated parts. A form ring 24 is removably secured to thepunch holder 23 in any conventional manner. Blocks 22 normally taketheir open or retracted position, as shown in Figure 7, by the action ofsprings 25. The springs 25 cooperate with cam heel blocks 26 and theheads of bolts 27 which are secured to the slide form blocks 22 in themanner shown. When the punch holder 23 is lowered, the form blocks 22are drawn together by cams 28 to the position shown in Figure 8. Duringthis operation the cams 28 strike the tapered or conical surface 22a ofthe slide form blocks 22 and force theminto the closed position, thusgripping blank 11 about the flange 13. The cam heel blocks 26 act asbearing surfaces for the cams 28 when they are lowered. The form ring 24is recessed at 24a to receive the top ofblank 11.

The slide form blocks 22 are each provided with annular recesses 22b forshaping the lower half of the bulge 1 4 while the form ring 24 isprovided with a similar annular recess 24b which serves as a mold forthe upper half of the bulge 14.

The form punch 21 which engages the lower portion of blank 11 isprovided with a block of rubber 29 as shown in Figure 7, which acts. asan expander as hereinafter'described; This rubberblock 29 is made ofdense rubber of so-called bumper stock," or its equivalent, whichhas atoughness and resiliency corresponding to thecommonly known vulcanizedtire-tread stock. The diameter of the rubber block 29 is substantiallythe same as the internal diameter of the blank 11 so that the blank canbe easily placed thereon. However, the height of the rubber block 29 issuch that when the blank 11 is in place as shown in Figure 7, the flange13 thereof will be spaced slightly from the corresponding surface of theform punch 21 for purposes described hereinafter.

Figure 8 shows the position of the elements at the conclusion of theoperation for forming the bulge 14, as shown in Figure 5. I

In starting this operation, the stamping device'appears as shown inFigure 7. When the punch holder 23 is lowered the-cams 28 draw the slideform blocks 22 together. Thus,'the inner edge of the blocks 22 willstrike the upper surface-of the flange 13 and by a carnming action, willdraw the blank 11 downward till it is seated on the form punch 21, thuscompressing the rubber block so it will be engaged snugly at all pointsagainst the inner surface of the blank 11. At the same time, the formring 24 descends and fits over the blank 11 and exerts pressure upon thebase 12 of the blank tending to crush the cylindrical walls. However,the rubber block 29 prevents the walls from bending inwardly due to theinitialcompression of the block as well as the further compression bythe form ring 24. The rubber block 29 will bulge and thus force thewalls of the blank outwardly and into the mold provided by recesses 22band 24b. When the form ring 24 and slide form blocks 22 have beenbrought completely together as shown in Figure 8, the recesses 22!: and24b define the outer limits of the bulge 14. The rubber block 29 pushesthe walls of the blank 11 outwardly as they are being crushed, thusshaping the blank as shown in Figure 5. It is to be particularly notedthat the bulge 14 is not formed only by the radial pressure exerted onthe cylindrical walls bythe rubber block 29 but also by the pressureexerted by the form ring 24 on the base 12 as it descends and tends tocrushthe blank 11. The principal functionof the rubber block 29 is totrigger the walls of the blank. 11 as they are crushed by the form ring24 and thus start their outward bending. However, the rubber block 29continues to exert some pressure. on the. walls all through thisoperation so that 4 the metal is pressed firmly into the recesses 22band 24b, thus forming a smooth, uniform bulge in the walls.

After the bulge 14 has been formed, the next step is to crimp the bulgeso as to form the inner flange 15, as shown in Figure 6. This isaccomplished by stamping the bulged blank 11 in the manner shown inFigure 9. In this view many of the elements are the same as those shownin Figures 7 and 8 and serve the same purpose. However, those elementswhich stamp or press the blank 11 are different. A form punch 30 ismounted on the die holder 24) and is shaped to support the blank 11around the outer flange 13. The form punch 30 is provided with an axialhole 31 which is adapted to receive a punch as described furtherhereinafter. Another hole 32 is provided in the form punch 30 spacedfrom the axial hole 31, for purposes described below. The slide formblocks 33, which are operated and controlled in the same manner as inFigures 7 and 8, are shaped to cooperate with the the form punch 30 soas to grip the'flange 13 of the blank when the press is actuated;However, the blocks 33 are provided with an inwardly sloping conicalsurface 33a around the center to receive and crimp the lower half ofbulge 14.

A form ring3'4 is secured to the punch holder 23 and is provided with anoutwardly extending conical surface 34:: adapted to cooperate with thesurface 33a to receive and crimp the upper half of the bulge 14 to formthe inner flange 15. The form ring 34 is also provided with a centrallylocated depression 34b to receive the baseor web 12 of the blank 11. Apunch 35 and one or more punches 36 are provided in the depression 34bto cooperate with holes 31 and 32, respectively, for punching holes inthe base 12 of the blanks. The central hole which is cut out by thepunch 35 enables the finished pulley to be mounted on a shaft or otherrotatable element and'the smaller hole cut out by the punch 36 is forreceiving one or more locking bolts or pins.

In operation, the blank 11 which has been stamped to provide the bulge14 as shown in Figure 5 is placed upon the form punch 30 and the punchholder is lowered. The slide form blocks 33 are contracted by means ofthe cams 28 so as to. grip the flange 13 of the blank 11. At the sametime the form ring 34 engages the web 12. of the blank in the depression34b aswell as the bulge 14 on the conical surface 34:: and crushes thebulge against the conical surface 33a of the blocks 33. By thisoperation the bulge 14 is transformedinto the inner flange 15, as shownin Figure 6. Near the end of the downward travel of the punch holder 23,the punches 35 and'36 will punch the holes as referred to above, thuscompleting'the pulley. In this final operation, in which the bulge 14 isfolded along a median annular fold line, the groove 16 of the pulley isaccurately sized and substantially coined about the inner annulargroove-sizing ridge of the form block 33. By maintaining a highfinish'on this ridge, a smooth finish is obtained in the groove 16 andaccurate 60116611? tricity of the groove 16 is obtained due-to thepunching of the shaft and locking bolt holes by the punches 35 and 36simultaneously with the sizing of the groove 16. It is also to be notedthat the equal gauge of metal shown throughout the pulley mayactually'be obtained; In fact, instead ofthinning the metal by drawing,the formation of the groove 16 is obtained by bulging or folding themetal under a crushing load, thereby tend ing to upset the metal ratherthan drawing it.

To form a double-V pulley, such as may housed on an automobilecrankshaft to provide a separate drive for the generator and water pumpor pumps, it is usually'preferable to provide the inner groove with aslightly smaller diameter than the outer groove in order to providesupport for the rootor; the inner groove; as will be explained inconnection with Figures 10 to 15 of the drawings; Similarly, if morethan two grooves are desired, it is preferable that the diameter of thegrooves decrease progressively toward the web of the pulley.

To form a double-V pulley, a shouldered cup 110 is stamped byconventional methods to provide a starting blank corresponding to thesingle groove pulley at the stage shown in Figure 4. As shown in Figure10, the cup or blank 110 is comprised of a base or web 111 and an upperwall 112 joined to a lower wall 113 by a sloping shoulder 114. The lowerwall 113 terminates in a sloping flange 115 which constitutes the outerflange of the pulley to be formed; the flange 115 is, in turn,preferably provided with a depending stiffening flange or bead 116. Thediameter of the wall 112 is preferably substantially the diameter of theroot of the inner V-groove and the diameter of the lower wall 114 ispreferably the diameter of the root of the outer V- groove. The lengthof the wall 114 and the shoulder 113 is, therefore, the length of theinner flange of the outer groove and the outer flange of the innergroove plus the length of the web which may be desired between thegrooves. The blank 110 is preferably formed so that the gauge of themetal in the walls and shoulder is substantially uniform; the gauge ofthe flange 115 may be equal to that of the walls and shoulders but ispreferably rolled so that it is approximately ten percent heavier. By soproviding a heavier gauge for the flange 115, a stiffer and strongerouter pulley flange is provided.

The stamping press, die holders, and camming mechanism for forming themultiple-V pulley are substantially identical with that shown in Figures7 to 9 and, accordingly, Figures 11, 12, 14, l5, l7 and 18 simply showthe particular slide form blocks and rings employed.

As indicated in Figure 11, the blank 110 is first bulged by crushing theblank in a form ring 120 against a rubber punch block 121 similar to theblock 29. As indicated, the form ring 120 is provided with a recess 122to receive the upper part of the bulge 123 formed from the shoulder 113and lower wall 114 of the blank 110. The lower part of the bulge 123 isreceived in a recess 124 in the form block 125, which also engages andconfines the flange 115 and bead 116 before and during the bulgingoperation against the form punch 126.

received in a recess 146 which constitutes the upper surface of theupper ridge 147 of the form block 148, the lower surface of the ridge147 engaging the sized flange 132. The block 148 is provided with alower ridge 149'- at the root of the inner V-groove. By so engaging theDuring this first bulging operation, the bead 116 serves the function ofstiffening the flange 115 and preventing its warping during bulging,thereby easing the load on the inner ridge 127 of the form block 125. Inmany instances it is advantageous to allow the bead 116 to remain on theblank 110 and the finished pulley, but in this particular instance, thebead 116 is trimmed away (in trimming dies not shown) before thecollapsing operation shown in Fig. 12.

The first bulge 123 is next collapsed to form the approximate outergroove 130 of the pulley, the grooveconnecting web 131 and the outerflange 132 of the inner groove. As indicated in Figure 12, the apparatusfor so collapsing the bulge 123 comprises simply a form ring 133 havinga lower annular beveled inner edge 134 which engages the upper portionof the bulge 123 to form the flange 132 as the inner flange 135 of theouter groove 130 and the connecting web 131 are formed against thestepped ridge 137 of the form block 136. During this collapsingoperation, the flange 115 is confined between the ridge 137 and the formpunch 138. As indicated, a rubber punch block is not necessary duringthis collapsing operation.

After approximate formation in the collapsing dies of Figure 12, theouter groove 130, connecting web 131 and flange 132 are accurately sizedand finished in the finishing rolls 140 and 141 shown in Figure 13.

After accurate sizing and finishing of the groove 130 and flange 132,the blank is again bulged in a form 7 ring 142 against a rubber punchblock 143, the form ring 142 having a recess 144 to receive the upperportion of the bulge 145. The lower portion of the bulge 145 is root ofthe inner groove, the form punch 1S0 holds the flange 132 to size andalso supports the point of the upper ridge 147.

After the second bulging operation, the'bulge 145 may be collapsed androll-finished (as was the bulge 123) to form the inner groove 160. Forstrength and rigidity, however, it is preferable to fold the bulge 145on its median line in a collapsing and finishing die comprised of a formring 151 having a conical recess to shape the remalnder of the wall 112to provide the conical shoulderv 153 desired for this particular pulley.The form ring' 151 is provided with a seat 154 which engages the upperportion of the bulge 145 and foldsthe bulge against the upper ridge 155of the form block 156. The form block is provided with a lower ridge 157which fits the lower groove 130 and confines it against the form punch157. It is to be noted that the form punch 157 extends upwardly toengage the root of the inner groove and the edge of the ridge 155. Thereentrantly folded'inner flange 158 of the groove 160 provides stiffnessand rigidity. This final folding operation accurately sizes and finishesthe groove 160. Suitable punches are preferably carried by the ring andholes are provided in the punch 157 to provide suitable shaft andlocking bolt holes in the web of the completed pulley shown in Figure16.

Although the support of the form punches available when the inner grooveof the pulley is of a lesser diameter than the outer groove makes suchmulti-V pulleys desirable, it is possible to produce a pulley havingequal groove diameter, as shown in Figures 17 and 18. In this modifiedconstruction, the outer groove is formed in the outlined manner, but inthe second bulging operation shown in Figure 17, the modified form punch150a extends up to the root of the groove to hold the size of the rootand support is provided for the modified ridge 14711 by means of anauxiliary rubber ring 143a. In collapsing the bulge 145a so formed, asshown in Figure 18, an auxiliary rubber ring 143b is employed to supportthe ridge 155a while the form punch 157a extends past the root of thegroove to hold the groove to size.

It should be apparent from the foregoing that a repetition of theoperations set forth above is to be employed for producing more than twoV-grooves, except that the folding operations shown in Figures 15 and 17are reserved for the innermost groove. The grooves formed in the pulleysshown in Figures 10 to 17 come to an apex and provide a sharp V, beingintended for the relatively recently developed small V-section belts. Itshould be obvious that the more conventional V-grooves, as shown in thepulley of Figure 6, may be formed in multiple-V pulleys and, also, thatthe webs between the grooves may be greater or lesser than that shown inthe pulley of Figure 15. The bottom of the cup or blank 110 may bevariously fabricated to provide a web for the pulley. Accordingly,therefore, this invention is not limited to the specific embodimentsdisclosed, either in whole or in part, but may be modified by thoseskilled in the art without departing from the scope of the invention asdefined in the following claims.

What is claimed is:

1. The method of making a multiple groove V-belt pulley from sheet metalcharacterized by a plurality of axially spaced concentric grooves inwhich the diameters of the grooves do not increase from the outermostgroove to the innermost groove, comprising the steps of form theouter-groove of; the pulley, simultaneously transmittingian axialcompressive force along said cup wall and applying an outward transaxialforce to an annular portion; of said cup wall to form an annular bulgein the wall of; said cup above said flange, said forces being appliedwhile confining saidflange, collapsing and sizing said bulge to form theinner flange of the outer groove ofsaid pulley, the outer flange of theadjacent groove,

and the web connecting said second and third mentioned flanges, whileconfining said first flange, and repeating said steps oi bulging thewall of; said cup abovethe most recently formed outer flange andcollapsingsaid bulge to tor-m aninner flange for said most recentlyformed outer. flange while confining said outer flange until the dieirednumber of p lley g o m d- 2-.- T e m h d of; m k g a mul p groove epulley iron sheetrnetal characterized by a plurality of axially spacedconcentric grooves in which the diameters oi the grooves progressivelydecrease from the outermost groove to the innermost groove comprisingthe steps of the method of claim 1. and including the step of rigidlysupporting the root of the most recently formed outer flangewhile thecup wall is being subjected to an axial compressive force to bulg thecupwall above said most recently formed outer flange and while saidbulge is beingcollapsed-to'forrn an inner flange for said outer flange.

3- Th m hod of. a in a mu t p r o l Pulley from, sheet, metal as definedin claim 1 including the step of folding the bulge for the finalinnermost groove about a median fold line by subjecting the opposingsides of said bulge to opposing compressive forces until a double-wallinner flange is formed.

References Cited in the file of this patent UNITED STATES PATENTS1,286,384 Mezger Dec. 3, 1918 1,609,380 Murray et a1. Dec. 7, 19261,610,588 Rawson Dec. 14, 1926 1,700,416 Nelson Jan. 29, 1929 1,711,182Shrum Apr. 30, 1929 1,748,452 Martins Feb. 25, 1930 1,756,592 HarrisonApr. 29, 1930 1,766,098 Booth -2 June 24, 1930 1,879,663. Dreyer Sept.27, 1932 1,928,911 Riemenschneider Oct, 3, 1933 1,995,907 Stoll Mar. 26,19.35 2,006,691 Giesler July 2, 1935 2,044,379 Brennan June 16, 19362,092,571 Cole Sept. 7, 1937 2,132,002, Hight Oct. 4, 1938 2,162,735Lyon June 20, 1939 2,330,228 Lyon Sept. 28, 1943 2,358,984 Lyon Sept.26, 1944 2,493,053 Zatylto Jan. 3, 1950 2,507,194 .Chyba- May 9, 1950

